Histoplasmosis: update 1989.

Histoplasmosis is a relatively mature disease that was first described 85 years ago. Histoplasmosis was long thought to be a rare and uniformly fatal illness. However, widespread use of skin testing in the 1940s proved that it was a common infection, especially in the central United States, and almost invariably benign. Primary histoplasmosis often presents as a self-limited, nonspecific respiratory infection, and thus, it was realized that a huge iceberg of subclinical and mildly symptomatic cases had been missed for years, since only the highly symptomatic and progressive infections had been diagnosed. Once the disease was recognized as a common one, many new clinical forms of the illness were recognized, including diffuse infiltrates due to heavy exposure, chronic cavitary disease resembling tuberculosis, and complications of primary infection, including mediastinal granuloma and the superior vena caval syndrome. Despite the mature state of histoplasmosis, it is still a disease capable of producing surprises. In this article, the history of histoplasmosis is reviewed, as well as current major concepts about the epidemiology, pathogenesis, clinical features, diagnosis, and treatment of this infection. Newer developments are then highlighted using the same outline.